U.S. patent number 11,441,085 [Application Number 17/138,009] was granted by the patent office on 2022-09-13 for process to make finished base oils and white oils from dewaxed bulk base oils.
This patent grant is currently assigned to Chevron U.S.A. Inc.. The grantee listed for this patent is Chevron U.S.A. Inc.. Invention is credited to Jifei Jia, Guan-Dao Lei, Jay Parekh, Kenny Peinado, Guang Zhang, Yihua Zhang.
United States Patent |
11,441,085 |
Peinado , et al. |
September 13, 2022 |
Process to make finished base oils and white oils from dewaxed bulk
base oils
Abstract
Provided in one embodiment is an improved and more flexible
process for preparing a finished base oil or a white oil product
comprising passing a dewaxed base oil product to a distillation
column and separating the dewaxed base oil product into fuel and
base oil product streams. The base oil product streams are tested
to determine if they meet desired specifications. Base oil product
streams that meet the desired minimum base oil specifications are
passed to a hydrofinishing reactor to prepare a white oil product,
or passed to direct sale.
Inventors: |
Peinado; Kenny (San Ramon,
CA), Parekh; Jay (Albany, CA), Jia; Jifei (Hercules,
CA), Zhang; Yihua (San Ramon, CA), Lei; Guan-Dao (San
Ramon, CA), Zhang; Guang (San Ramon, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
Chevron U.S.A. Inc. |
San Ramon |
CA |
US |
|
|
Assignee: |
Chevron U.S.A. Inc. (San Ramon,
CA)
|
Family
ID: |
1000006554744 |
Appl.
No.: |
17/138,009 |
Filed: |
December 30, 2020 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20220204874 A1 |
Jun 30, 2022 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10M
177/00 (20130101); C10M 101/02 (20130101); C10G
67/02 (20130101); C10G 2300/308 (20130101); C10G
2300/202 (20130101); C10G 2300/304 (20130101); C10M
2203/1006 (20130101); C10G 2400/10 (20130101); C10N
2070/00 (20130101); C10G 2400/14 (20130101); C10G
2400/04 (20130101); C10G 2300/302 (20130101) |
Current International
Class: |
C10G
67/02 (20060101); C10M 177/00 (20060101); C10M
101/02 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Boyer; Randy
Assistant Examiner: Valencia; Juan C
Attorney, Agent or Firm: Gess; E. Joseph Hayworth; Melissa
M. Warzel; Mark L.
Claims
That which is claimed is:
1. A process for preparing base oil from a waxy hydrocarbon
feedstock comprising: a) contacting the hydrocarbon feedstock in a
hydroisomerization zone under hydroisomerization dewaxing
conditions; b) collecting a dewaxed product stream from the
hydroisomerization zone and passing the product streams to a
distillation column; c) separating the dewaxed product stream into
fuel and base oil products in the distillation column; d) testing
the base oil products to determine if they meet minimum desired
specifications; e) passing a base oil product which meets the
minimum desired specifications for a base oil to a hydrofinishing
reactor to meet more stringent specifications, or to a further use
or direct sale; and f) collecting a base oil product stream from
the hydrofinishing reactor and testing for readily carbonizable
substances.
2. A process of claim 1, wherein the dewaxed product is separated
into a diesel fuel product stream and up to least four base oil
product streams.
3. The process of claim 2, wherein the base oil products include
XLN base oil, LN base oil, and MN base oil.
4. The process of claim 1, wherein the desired minimum
specifications include pour point, viscosity and viscosity
index.
5. The process of claim 1, wherein the hydrofinishing reactor
comprises a hydrofinishing catalyst and the hydrofinishing catalyst
comprises a silica alumina based catalyst further containing
platinum and/or palladium.
6. The process of claim 1, wherein the base oil product stream
collected from the hydrofinishing reactor is also tested for UV
absorbance (ASTM D2269).
7. The process of claim 1, wherein the base oil stream that fails
to meet the desired specifications is recycled to the
hydroisomerization zone in a).
8. A process for preparing a white oil product comprising: a)
passing a dewaxed base oil product to a distillation column and
separating the dewaxed base oil product into a diesel fuel product
and up to four base oil products; b) testing the base oil products
to determine if they meet minimum desired specifications; and c)
passing a base oil product which meets the desired specifications
to a hydrofinishing reactor to then meet white oil
specifications.
9. The process of claim 8, wherein the minimum desired
specifications include pour point, viscosity and viscosity
index.
10. The process of claim 8, wherein a product from the
hydrofinishing reactor is subjected to the RCS (readily
carbonizable substances) test ASTM D 565-88.
11. The process of claim 10, wherein the product is also tested for
UV absorbance by ASTM D2269.
12. The process of claim 8, wherein the up to four base oil
products include XLN base oil, LN base oil, and MN base oil.
13. The process of claim 8, wherein the hydrofinishing reactor
comprises a hydrofinishing catalyst and the hydrofinishing catalyst
comprises a silica alumina based catalyst further containing
platinum and/or palladium.
Description
TECHNICAL FILED
Process for preparing high quality base oils and white oil from a
dewaxed hydrocarbon feedstock.
BACKGROUND
High quality lubricating oils are critical for the operation of
modern machinery and motor vehicles. Finished lubricants used for
automobiles, diesel engines, axles, transmissions, and industrial
applications consist of two general components, a base oil and one
or more additives. Base oil is the major constituent in these
finished lubricants and contributes significantly to the properties
of the finished lubricant. In general, a few base oils are used to
manufacture a wide variety of finished lubricants by varying the
mixtures of individual base oils and individual additives. Most
crude oil fractions require moderate to significant upgrading to be
suitable for lubricant manufacture. As an example, high-quality
lubricating oils must often be produced from waxy feeds. Numerous
processes have been proposed for producing lubricating base oils by
upgrading ordinary and low quality feedstocks.
Hydrocarbon feedstocks may be catalytically dewaxed by
hydrocracking or hydroisomerization. Hydrocracking generally leads
to a loss in yield due to the production of lower molecular weight
hydrocarbons, such as middle distillates and even lighter C.sub.4-
products, whereas hydroisomerization generally provides higher
yields by minimizing cracking.
U.S. Pat. No. 8,475,648 describes processes and a catalyst for
dewaxing a heavy hydrocarbon feedstock to form a lubricant base
oil. A layered catalyst system is used. See also U.S. Pat. No.
8,790,507. U.S. Pat. No. 8,192,612 describes processes for
preparing a base oil slate from a waxy feed. The disclosure of the
foregoing patents are incorporated herein by reference in their
entirety.
The flexibility of the overall process, however, can have a large
impact on the economic viability of the base oil process. The need
for improved processes offering more flexibility and hence greater
economic benefits in preparing high quality base oils, and white
oil products, is important to the industry.
SUMMARY
Provided in one embodiment is a process for preparing a finished
base oil or a white oil product comprising passing a dewaxed bulk
base oil to a distillation column and separating the dewaxed bulk
base oil into fuel and base oil products. The base oil products are
tested to determine if they meet desired specifications. In one
embodiment, the specifications include pour point, viscosity and
viscosity index. The base oil products which meet these minimum
desired specifications for base oils might be passed to a final use
or a direct sale. To make white oils and/or meet a more stringent
aromatics specification, the base oil products might be passed to a
hydrofinishing reactor.
In one embodiment, a process is provided for preparing base oils
from a waxy hydrocarbon feedstock. The process comprises contacting
a hydrocarbon feedstock in a hydroisomerization zone under
hydroisomerization dewaxing conditions. A dewaxed product is
collected from the hydroisomerization zone and passed to a
distillation column. The dewaxed bulk product is separated into
fuel and base oil products by the distillation column. The base oil
products are tested to determine if they meet desired
specifications. In one embodiment, the specifications include pour
point, viscosity and viscosity index. The base oil products which
meet these minimum desired specifications for base oils might be
passed to a final use or a direct sale. To make white oils and/or
meet a more stringent aromatics specification, the base oil
products might be passed to a hydrofinishing reactor.
Among other factors, the present processes offer greater
flexibility and control over the base oil process. The analysis of
the separated base oil streams obtained from the dewaxed bulk base
oil prior to hydrofinishing permits choices and a tailoring of
reaction conditions to create an improved economic process for
obtaining high quality, useable base oils as well as white
oils.
BRIEF DESCRIPTION OF THE DRAWING
The drawing depicts one embodiment of the present process.
DETAILED DESCRIPTION
The present process makes finished base oils and white oils from a
dewaxed bulk base oil. Once a hydrocarbon feedstock is dewaxed, the
resulting dewaxed bulk base oil is distilled and fractionated into
different grades of base oils and fuels. Each grade of base oil is
analyzed to determine whether it passes relevant or desired base
oil specifications. In one embodiment, the specifications include
pour point, viscosity and viscosity index. The specifications
differ for each grade of base oil, with acceptable specifications
well known in the industry. Other tests can include UV for
aromatics, cloud point or Noack. The specifications considered will
always differ based on the ultimate intended product.
If the base oil passes the test(s) and meets the suitable
specifications, it can be passed on for direct use or direct sale,
e.g., as premium base oils. Thus, no further processing is required
of these base oil streams. Focus and tailoring of reaction
conditions in the hydrofinishing reactor can then be asserted on
the remaining streams. Of course, if desired, even if a particular
base oil type stream passes the tests, it can still be processed to
make a finished base oil and or a white oil by hydrofinishing. If
the intention is to make white oil, then most if not all of the
base oil products can be passed to hydrofinishing.
Depending on the reactor temperature and pressure used in the
hydrofinisher, the final product can be considered a finished base
oil or a white oil product. The reactor temperature and pressure
can be tailored for the base oil stream being processed to thereby
insure the highest quality product. A white oil product can be
suitable for and safely used in food processing equipment. It must,
however, meet the requisite stringent specifications, including the
RCS (readily carbonizable substances) test as in ASTM D 565-88.
If a base oil does not meet the necessary requirements, it can be
recycled to the dewaxer or passed to further processing.
By utilizing the testing/analysis of the base oil products obtained
by the distillation/fractionation, the present process has been
found to offer greater flexibility in the overall process. Instead
of passing the entire dewaxed bulk base oil to a hydrofinisher, the
present process offers a choice for each of the base oil products
recovered. Less base oil need be subjected to hydrofinishing. And,
when the choice is made to pass the base oil onto hydrofinishing,
the system can be operated at more flexible conditions including
feed rate, temperature and hydrogen pressure. The conditions can
also be tailored to that base oil type product to insure a high
quality finished base oil or white oil product.
Another important advantage is that only one hydrofinishing is used
in the present process. Typically, an entire dewaxed product is
passed from the dewaxing reactor to a hydrofinisher. The product
from the hydrofinisher is then passed to a distillation column. The
distillation column can develop compounds which might cause failure
of an RCS test, thereby limiting the role of the oil as a white oil
product unless the base oil is again hydrofinished. Thus, two
hydrofinishing runs become necessary. In the present process,
however, the distillation column precedes the hydrofinisher and
thereby avoids such an unfortunate result. The present process is
therefore much more efficient.
In one embodiment, to obtain the dewaxed bulk base oil, a waxy
hydrocarbon feed is subjected to a dewaxing process. The term "waxy
feed" as used in this disclosure refers to a feed having a high
content of normal paraffins (n-paraffins). A waxy feed useful in
the practice of the present process scheme will generally comprise
at least 40 wt. % n-paraffins, preferably greater than 50 wt. %
n-paraffins, and more preferably greater than 75 wt. % n-paraffins.
Preferably, the waxy feed used in the process will also have very
low levels of nitrogen and sulfur, generally less than 25 ppm total
combined nitrogen and sulfur and preferably less than 20 ppm. This
can be achieved by hydrotreating before dewaxing.
A wide variety of hydrocarbon feedstocks can be used, including
whole crude petroleum, reduced crudes, vacuum tower residua,
synthetic crudes, Fischer-Tropsch derived waxes, and the like.
Typical feedstocks can include hydrotreated or hydrocracked gas
oils, hydrotreated lube oil raffinates, brightstocks, lubricating
oil stocks, synthetic oils, foots oils, Fischer-Tropsch synthesis
oils, high pour point polyolefins, normal alphaolefin waxes, slack
waxes, deoiled waxes and microcrystalline waxes. Other hydrocarbon
feedstocks suitable for use in processes of the present process
scheme may be selected, for example, from gas oils and vacuum gas
oils; residuum fractions from an atmospheric pressure distillation
process; solvent-deasphalted petroleum residua; shale oils, cycle
oils; animal and vegetable derived fats, oils and waxes; petroleum
and slack wax; and waxes produced in chemical plant processes.
In an embodiment, the hydrocarbon feedstocks can be described as
waxy feeds having pour points generally above about 0.degree. C.,
and having a tendency to solidify, precipitate, or otherwise form
solid particulates upon cooling to about 0.degree. C. Straight
chain n-paraffins, either alone or with only slightly branched
chain paraffins, having 16 or more carbon atoms may be referred to
herein as waxes. The feedstock will usually be a C.sub.10+
feedstock generally boiling above about 350.degree. F. (177.degree.
C.). In contrast, the base oil products of the present processes,
resulting from hydroisomerization dewaxing of the feedstock,
generally have pour points below 0.degree. C., typically below
about -12.degree. C., and often below about -14.degree. C.
The present process scheme may also be suitable for processing waxy
distillate stocks such as middle distillate stocks including gas
oils, kerosenes, and jet fuels, lubricating oil stocks, heating
oils, and other distillate fractions whose pour point and viscosity
need to be maintained within certain specification limits.
Feedstocks for processes of the present process scheme can, in one
embodiment, include olefin and naphthene components, as well as
aromatic and heterocyclic compounds, in addition to higher
molecular weight n-paraffins and slightly branched paraffins.
During processes of the present scheme, the degree of cracking of
n-paraffins and slightly branched paraffins in the feed is strictly
limited so that the product yield loss is minimized, thereby
preserving the economic value of the feedstock.
In an embodiment, the feedstock may comprise a heavy feed. Herein,
the term "heavy feed" may be used to refer to a hydrocarbon
feedstock wherein at least about 80% of the components have a
boiling point above about 900.degree. F. (482.degree. C.). Examples
of heavy feeds suitable for practicing the present process scheme
include heavy neutral (600N) and bright stock.
According to one aspect of the present processes, a wide range of
feeds may be used to produce lubricant base oils in high yield with
good performance characteristics, including low pour point, low
cloud point, low pour-cloud spread, and high viscosity index. The
quality and yield of the lube base oil product of the instant
process may depend on a number of factors, including the
formulation of the hydroisomerization catalysts comprising the
layered catalyst systems and the configuration of the catalyst
layers of the catalyst systems.
According to one embodiment of the present process scheme, a
catalytic dewaxing process for the production of base oils from a
waxy hydrocarbon feedstock may involve introducing the feed into a
reactor containing a dewaxing catalyst system. Hydrogen gas may
also be introduced into the reactor so that the process may be
performed in the presence of hydrogen, e.g., as described herein
below with reference to the process conditions.
Within the reactor, the feed may be contacted with a hydrotreating
catalyst under hydrotreating conditions in a hydrotreating zone or
guard layer to provide a hydrotreated feedstock. Contacting the
feedstock with the hydrotreating catalyst in the guard layer may
serve to effectively hydrogenate aromatics in the feedstock, and to
remove N- and S-containing compounds from the feed, thereby
protecting the first and second hydroisomerization catalysts of the
catalyst system. By "effectively hydrogenate aromatics" is meant
that the hydrotreating catalyst is able to decrease the aromatic
content of the feedstock by at least about 20%. The hydrotreated
feedstock may generally comprise C.sub.10+ n-paraffins and slightly
branched isoparaffins, with a wax content of typically at least
about 20%.
Hydroisomerization catalysts useful in the dewaxing process
typically will contain a catalytically active hydrogenation metal.
The presence of a catalytically active hydrogenation metal leads to
product improvement, especially VI and stability. Typical
catalytically active hydrogenation metals include chromium,
molybdenum, nickel, vanadium, cobalt, tungsten, zinc, platinum, and
palladium. The metals platinum and palladium are especially
preferred. If platinum and/or palladium is used, the total amount
of active hydrogenation metal is typically in the range of 0.1 wt.
% to 5 wt. % of the total catalyst, usually from 0.1 wt. % to 2 wt.
%.
The refractory oxide support may be selected from those oxide
supports, which are conventionally used for catalysts, including
silica, alumina, silica-alumina, magnesia, titania and combinations
thereof.
In one embodiment, the dewaxing process involves using a layered
catalyst system. The layered catalyst system may comprise first and
second hydroisomerization catalysts, wherein the first
hydroisomerization is disposed upstream from the second
hydroisomerization catalyst. The first hydroisomerization catalyst
may have a first level of selectivity for the isomerization of
n-paraffins, the second hydroisomerization catalyst may have a
second level of selectivity for the isomerization of n-paraffins.
In an embodiment, the first and second levels of selectivity may be
the same or at least substantially the same.
The conditions under which the dewaxing process is carried out will
generally include a temperature within a range from about
390.degree. F. to about 800.degree. F. (199.degree. C. to
427.degree. C.). In an embodiment, each of the first and second
hydroisomerization dewaxing conditions includes a temperature in
the range from about 550.degree. F. to about 700.degree. F.
(288.degree. C. to 371.degree. C.). In a further embodiment, the
temperature may be in the range from about 590.degree. F. to about
675.degree. F. (310.degree. C. to 357.degree. C.). The pressure may
be in the range from about 15 to about 3000 psig (0.10 to 20.68
MPa), and typically in the range from about 100 to about 2500 psig
(0.69 to 17.24 MPa).
Typically, the feed rate to the catalyst system/reactor during
dewaxing processes of the present invention may be in the range
from about 0.1 to about 20 h.sup.-1 LHSV, and usually from about
0.1 to about 5 h LHSV. Generally, dewaxing processes of the present
invention are performed in the presence of hydrogen. Typically, the
hydrogen to hydrocarbon ratio may be in a range from about 2000 to
about 10,000 standard cubic feet H.sub.2 per barrel hydrocarbon,
and usually from about 2500 to about 5000 standard cubic feet
H.sub.2 per barrel hydrocarbon.
The above conditions may apply to the hydrotreating conditions of
an optional hydrotreating zone, as well as to the
hydroisomerization conditions. The reactor temperature and other
process parameters may vary according to factors such as the nature
of the hydrocarbon feedstock used and the desired characteristics
(e.g., pour point, cloud point, VI) and yield of the base oil
product.
The bulk base oil product is passed to a distillation column, which
can be a vacuum distillation tower, to separate the product into
fuel and different base oil type products. The distillation column
is generally run under conventional conditions to effect a
separation of fuel and various base oil products.
Base oils recovered from the distillation column can include a
range of base oils grades. Typical base oil grades recovered from
the distillation column include, but are not necessarily limited
to, XXLN, XLN, LN, and MN. An XXLN grade of base oil when referred
to in this disclosure is a base oil having a kinematic viscosity at
100.degree. C. between about 1.5 cSt and about 3.0 cSt, preferably
between about 1.8 cSt and about 2.3 cSt. An XLN grade of base oil
will have a kinematic viscosity at 100.degree. C. between about 1.8
cSt and about 3.5 cSt, preferably between about 2.3 cSt and about
3.5 cSt. A LN grade of base oil will have a kinematic viscosity at
100.degree. C. between about 3.0 cSt and about 6.0 cSt, preferably
between about 3.5 cSt and about 5.5 cSt. An MN grade of base oil
will have a kinematic viscosity at 100.degree. C. between about 5.0
cSt and about 15.0 cSt, preferably between about 5.5 cSt and about
10.0 cSt. In addition to the various base oil grades, a diesel
product may also be recovered from the distillation column.
Diesel fuels prepared/separated out as part of the product slate
will generally have a boiling range between about 65.degree. C.
(about 150.degree. C.) and about 400.degree. C. (about 750.degree.
C.), typically between about 205.degree. C. (about 400.degree. F.)
and about 315.degree. C. (about 600.degree. F.). The recovered
diesel fuel can be passed on to further processing or use.
The various base oil grades are tested. Generally, the testing
would include pour point, viscosity and viscosity index
determinations. Other tests might be made to analyze cloud point,
Noack or aromatic content. The requisite specifications will vary
for each grade of base oil, and desired specifications can vary
depending on the ultimate product desired. Once analyzed, it can be
determined if the particular base oil product meets the desired
specifications for the intended end use or is suitable for direct
sale as premium base oil. The base oil product can also be passed
to a hydrofinishing reactor.
Such hydrofinishing may be performed in the presence of a
hydrogenation catalyst, as is known in the art. The hydrogenation
catalyst used for hydrofinishing may comprise, for example,
platinum, palladium, or a combination thereof on an alumina
support. The hydrofinishing may be performed at a temperature in
the range from about 350.degree. F. to about 650.degree. F.
(176.degree. C. to 343.degree. C.), and a pressure in the range
from about 400 psig to about 4000 psig (2.76 to 27.58 MPa).
Hydrofinishing for the production of lubricating oils is described,
for example, in U.S. Pat. No. 3,852,207, the disclosure of which is
incorporated by reference herein.
The product from the hydrofinisher can be quality white oil. The
product is often tested to insure it meets the stringent
requirements to be used safely in food. The tests include the RCS
test (ASTM D 565-88). The tests might also include a UV absorbance
test (D2269).
Further illustration of the present process can be obtained upon a
review of the FIGURE of the Drawing and the following examples. The
flexibility and efficiency of the present process are described and
demonstrated. The FIGURE and the examples are merely meant to be
illustrative and not limiting.
EXAMPLE 1
Table 1 below summarizes the properties of a hydrodewaxed stream
that can be fed to a distillation column. The feed stream is a full
range bulk hydrodewaxed intermediate product, having a distillation
range from 426.degree. F. to 1355.degree. F. The pour point was
reduced to -44.degree. C. after the hydrodewaxing process. The UV
absorbance at 226 nm is around 0.0928, which indicates that the
aromatics content is .sup..about.0.45 wt. %.
TABLE-US-00001 TABLE 1 Properties of the Hydrodewaxed Stream Sample
Hydrodewaxed Stream API 41.5 Density at 15.6.degree. C., 0.818 g/cc
(D4052) Sulfur, ppm (D2622) <5 Aromatics by UV, wt. % 0.45 VI
(D2270) 178 Vis at 40.degree. C. (D445) 25.58 Vis at 100.degree. C.
(D445) 5.754 Pour Point, .degree. C. (D97) -44 RCS 15 UV absorbance
au. 226 nm 0.0928 255 nm 0.0127 272 nm 0.0123 305 nm 0.0039 310 nm
0.0027 340 nm 0.007 348 nm 0.006 385 nm 0.0000 435 nm 0.0000 450 nm
0.0000 495 nm 0.0000 Simdist wt. % , .degree. F. 0.5 426 5 542 10
598 30 744 50 854 70 983 90 1197 EP 1355
As illustrated by the process diagram in the FIGURE, the
hydrodewaxed stream is separated into 5 product streams through the
distillation column, including diesel, extra light neutral (XLN),
light neutral (LN), medium neutral (MN), and heavy neutral (HN).
Table 2 below summarizes the properties for all the distillation
products. All products can be used for direct sale as diesel or
Group III/III+ premium base oils. The UV absorbance at 226 nm is in
the range of 0.05 to 0.18, suggesting the aromatics content is
below 1% for all products. However, the Readily carbonizable
substances (RCS) test shows 17 for XLN, LN and MN. This is evidence
that the distillated base oil products do not meet food grade white
oil specifications.
TABLE-US-00002 TABLE 2 Distillation Products Properties Diesel XLN
LN MN HN Distillation Products API 47.2 43.5 42.2 39.8 36.5 Density
at 15.6.degree. C., g/cc 0.792 0.809 0.815 0.826 0.842 (D4052)
Sulfur, ppm (D2622) <5 <5 <5 <5 <5 Aromatics by UV,
wt. % 0.34 0.28 0.30 0.45 0.89 VI (D2270) 126 139 157 161 Vis at
40.degree. C. (D445) 4.555 10.75 15.85 38.89 218 Vis at 100.degree.
C. (D445) 1.634 2.922 3.845 7.341 27.37 Pour Point, .degree. C.
(D97) -58 -42 -37 -28 -23 RCS 15 17 17 17 -- UV absorbance au. 226
nm 0.0687 0.0563 0.0621 0.0912 0.1822 255 nm 0.0064 0.0086 0.0107
0.0165 0.0308 272 nm 0.0073 0.0075 0.0093 0.0147 0.0277 305 nm
0.0014 0.0021 0.0027 0.0053 0.0104 310 nm 0.0009 0.0014 0.0020
0.0039 0.0079 340 nm 0.0002 0.0007 0.0009 0.0013 0.0025 348 nm
0.0001 0.0004 0.0009 0.0012 0.0021 385 nm 0.0000 -0.0001 0.0001
0.0004 0.0006 435 nm 0.0000 -0.0001 0.0001 0.0001 0.0001 450 nm
-0.0001 -0.0001 0.0001 0.0001 0.0001 495 nm 0.0000 0.0000 0.0000
0.0000 0.0000 Simdist wt. %, .degree. F. 0.5 391 651 710 796 802 5
474 684 741 831 874 10 505 697 754 847 903 30 574 723 779 889 978
50 622 739 797 928 1049 70 663 754 815 971 1137 90 704 774 838 1031
1355 EP 749 810 878 1138 1355
EXAMPLE 2
The present process adds the flexibility to further upgrade the
base oil products to meet white oil specifications by sending the
individual base oil block to a hydrofinishing section. This is
shown in the FIGURE of the Drawing. The product can be further
upgraded to food grade or cosmetic grade by saturating aromatics to
reduce the aromatics content. The hydrofinishing section can be
optimized with minimal scale and investment because of the smaller
block flow. Moreover, the system can be operated at more flexible
conditions including feed rate, temperature and hydrogen
pressure.
The reactor in the hydrofinishing section is installed with a
hydrofinishing catalyst, which can comprise Pt/Pd and silica
alumina as disclosed in U.S. Pat. No. 8,790,507, the entirety of
which is incorporated herein by reference. The reaction was
performed under 1140 psig total pressure. The MN stream (as listed
in Table 2) was passed through the hydrofinishing reactor at a LHSV
of 2 hr.sup.-1. The hydrogen to oil ratio is about 3000 scfb. The
reactor was operated at 450 F. The hydrofinished base oil product
was analyzed for UV absorbance, RCS and ASTM D2269 (UV test after
DMSO extraction). The results are summarized in Table 3 and Table 4
below. The UV absorbance test shows that the 226 nm has been
reduced significantly after hydrofinishing and the aromatics
content was decreased from .about.0.45% to 0.001%. RCS and ASTM
D2269 tests show that the MN white oil product meets food grade
white oil specifications.
TABLE-US-00003 TABLE 3 MN White Oil Properties MN White Oil
Hydrofinished Product Aromatics by UV, wt % 0.001 VI (D2270) 157
Vis at 40.degree. C. (D445) 38.87 Vis at 100.degree. C. (D445)
7.339 Pour Point, .degree. C. (D97) -38 RCS 4 UV absorbance a.u.
226 nm 0.0002 255 nm 0.00007 272 nm 0.00005 305 nm 0.00009 310 nm
0.00011 340 nm 0.00003 348 nm 0.00003 385 nm 0.00001 435 nm 0 450
nm 0.00001 495 nm 0 Simdist wt %, .degree. F. 0.5 796 5 829 10 844
30 886 50 926 70 969 90 1029 EP 1123
TABLE-US-00004 TABLE 4 MN White Oil ASTM D2269 Test Results
Hydrofinished Product UV absorbance (ASTM D2269) MN White Oil
260-279 nm 0.068 280-289 nm 0.034 290-299 nm 0.037 300-329 nm 0.031
330-350 nm 0.016
As used in this disclosure the word "comprises" or "comprising" is
intended as an open-ended transition meaning the inclusion of the
named elements, but not necessarily excluding other unnamed
elements. The phrase "consists essentially of" or "consisting
essentially of" is intended to mean the exclusion of other elements
of any essential significance to the composition. The phrase
"consisting of" or "consists of" is intended as a transition
meaning the exclusion of all but the recited elements with the
exception of only minor traces of impurities.
Numerous variations of the present invention may be possible in
light of the teachings and examples herein. It is therefore
understood that within the scope of the following claims, the
invention may be practiced otherwise than as specifically described
or exemplified herein.
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